Contact device.



PATENTED JUNE 5, 1906.

K. TORNBERG. CONTACT DEVICE. APPLIGATION FILED Nov. s. 1904.

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' UNITED sTATEs PATENT oEEroE..

KNUT TORNBERG, OF LYNN, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

CONTACT DEVICE.

S'peccation of Letters Patent.

Patented June 5, 1906.

Application filed November 3, 1904. serial No, v231,201.

following is a specification.

My invention relates to contact-making devices for electric circuits, and is particularly adapted for use with electrically-controlled clocks or other synchronous devices or in apparatus the circuit of which is to be made and broken at predetermined times.

The object of my invention is to provide a device which is simple in construction, positive and reliable, and with a minimum friction in operation. An exceedingly simple and practically frictionless contact-making device consists of a closed tube with a globule of mercury contained therein. I have found experimentally, however, that with the ordinary construction, in which a globule of meroury is caused to move back and forth in a closed tube, the mercury eventually becomes sluggish and adheres to the sides of the tube. I have also discovered thatif the mercury instead of being caused to reciprocate ina tube is caused to travel continuously around an endless tube there is not the same tendency to become sluggish and to adhere.

One feature of myinvention consists in providing an endless closed tube which when reciprocatedcauses a globule of mercury contained therein to circulate around the tube. I accomplish this by providing a novel form of bent or twisted tube, as will be hereinafter described. In order to obtain a positive and reliable action of the contact-maker at theinstant when its operation is required, it is essential that a quick movement should be given to the tube at that instant.

Another feature of my invention consists in so arranging the connection between the driving means and the tube that 'with a steady or intermittent movement of the driving means a quick and certain movement is im arted to the tube at predetermined interva s. More specifically considered, this feature of my invention consists in the combination, with a rotating member, of a cam-shaped member adapted to be engaged and moved by the rotatin member and to be released .at predetermine intervals, so as to permit its sudden movement under the 'iniuence of gravity or other suitable force.

Other features of my invention will appear from ythe following specification and will be more specifically pointed out in the appended claims. I

My invention will best be understood by reference to the accompanying drawings, in which Figure 1 shows a side elevation of a contact device arranged in accordance with my invention. `Fig. 2 shows an end'elevation of' the same. Fig. 3 shows a plan view. Figs. 4 and 5 are dia ams showing the circuit connections; and igs. 6 to 10, inclusive, are diarams showing the connection between the` riving means and the tube-carrying member. In the drawings, A represents a pinion mounted on the shaft a, which is driven from the master-clock or other prime mover with which the controlled 'devices areto be synchronized.

B'represents a gear mounted on the shaft b anden aging the pinion A. I have shown the gear of twice the diameter of the pinion A, so that one revolution of the pinion produces half a revolution of the gear. The ear B carries a pinv b, (shown in Figs. 1 an 2,) which is adapted to engage a forked cam C, which is mounted on the shaft c. By the engagement between the pin b and the cam C the rotation of gear B produces a reciprocating movement of the cam, as will be hereinafter explained. Thus it will be seen that each revolution of the pinion A tips the cam C in one direction, and the following revolution tips it back to its original position. Also mounted rigidly on the shaft c is the member D, which is provided with a projection d, as shown in 2 adapted to engage either of the stopsl d, so as to limit the .movement of shaft c. The member D carries the contacttubes E E which are secured to the member' IOO IOS

.other at an angle.

The ends of these tubes areV bent, as shown in Fig. 1, so that the sides of the tube cross each Each tube contains a globule of mercury, as is indicated by G G in Fig. 3.

The operation` of the tubes will be eX- plained by reference to Fig. 4. In this figure l l represent leads from a source of current, and 3 4 represent leads to the electricallycontrolled clocks or other devices H. Assume that the globule of mercury is at the right-hand end of the front side of the tube. lt is then in contact with neither of the con-v tar-ts g or g/, since the latter contacts are placed in the back side of the tube, while the former are at the left-hand end of the front side, as is shown in Fig. 3. As long as the tube remains in the position shown the mercury has no tendency to move and the circuit of the "devices H will remain open. If the right-hand end of the tube is gradually raised until the front side of the tube passes the horizontal position, the mercury will move toward the left through the front side of the tube, momentarily engaging the contacts g and closing the circuit kof the devices H and then passing down the steeper incline at the left-hand'end of the tube and breaking the circuit. When the tube is tipped in the other direction, the mercury will pass back along the back side of the tube, making a mo mentary engagement with the contact g and returning to its original position. Thus when the tube is reciprocated in either direction the circuit of the devices H is momentarily closed.

In the drawings I have shown two tubes, one arranged with a greater bend than-the other, so that its sides have a greater inclination to the horizontal. The purpose of this is to obtain a reversal of current lin the controlled devices, since some electrically-controlled clocks and similar mechanisms are so arranged that such reversal is required. The connection of circuits is shown diagrammatically in Fig. 5. Assuming the mercury in both tubes to be' at the right-hand front end of both tubes, the mercuryin tube E will connect the contacts g, which are placed at the end of the tube, while the mercury in tube E will not con ect the contacts g3, which are placed in the back side of the tube. The position of the mercury in the two tubes is clearly shown in Fig. 3. Now if the righthand ends of both tubes are slowly raised the front side of the tube E will pass the horizontal position before the front side of the tube E', since the sides of the former tube have a smaller slope. The mercur in tube E will conse uently move tothe eft-hand end of the tu e connecting the contacts g. The circuit of the devices H is still open, however, since the mercury still remains at the righthand end of the front side of tube E. When the tubes have been tipped a little farther, i

however, the front side of tube E will pass the horizontal, and the mercury contained therein will move toward the left, momentarily connecting thecontacts g2. The circuit will then be momentarily closed, as follows: from lead 1 through contacts g2, lead 3, devices H, lead 4, contacts g, lead 2. circuit is instantly broken, however, by the mercuryin tube E passing down the steep ineline at the end of the tube and leaving contacts g2. When the tubes are tipped in the opposite direction, the mercury in tube E will iirst move toward the right `along the back side of the tube, reaching the righthand end of the tube and connecting contacts g. Later the mercury in tube E will follow, momentarily connecting contacts g3. A circuit will then be momentarily closed The I from lead l through the contact g3, lead 4, de--' vices H, lead 3, contact g, lead 2. Thus it is seen that this time the current will pass through the devices H in the opposite direction from that in which it passed when the circuit was closed the first time.

In order` to obtain a ositive and reliable action of the contacts, Ipso arrange the connection between the driving means and the tubes that the tubes are given a sudden quick movement at the instant when the mercury should move in the tube Ef This connection consists of the pin b, mounted on the gear B, and the forked cam C. The operation of this connection will be clear from an inspection of Figs. 6 to 10. The cam C is provlded with two opposite notches c and c3, which are formed by the extensions c? and c5, respectively. 'lhe right-hand side of notch c3 is formedby the shoulder c, as shown. In Fig. 6 the cam is shown in one extreme limit of its movement, in which stop d of Fig. 2'is in engagement with one of the sto s d.

ear B is supposed to be moving c ockwise, as indicated by the arrow. With the gear B in the position shown no movement of cam C is produced while the gear is turning through a certain arc. When the pin b engages the cam C, as indicated in Fig. 7, the cam is slowly moved toward the right, the pin b inally entering the notch c at the upper end of the cam. This is shown in Fig. 8, which. shows the position of the cam when the tubes are substantially horizontal. As'the gear B moves onward, pushing cam C to the ri ht, the center of gravity of the tubes and t eir support is shi ted to the right-hand side of the supporting-shaft c, so that the cam C tends to move to the right independently of the gear B. It is prevented from so moving, however, b y the extension c2 at the upper end of cam C until a sufficient inclination of the tubes has been produced to cause the mercury to movein the tube having the lesser slope, as has vbeen heretofore explained. After this movement has occured in the first tube, as the instant is reached at which con- IOC tact is required, the pin b passes from under the extension c2 and releases the cam C, so as to allow it to move suddenly to its extreme position, as shown in Fig. 9. By this sudden movement of the cam a positive and reliable movement of the mercury inthe second tube is obtained. rlhe cam remains in the position shown in Fig 9 until the pin b engages the extension c5, as shown in Fig 10. The cam isthen moved toward the left, the pin b passing down into the notch c3. The pin remains in this notch until the center of gravity of the tubes-has been moved to the opposite side of the shaft and the mercury has moved in the `first tube. The pin remains in the notch in engagement with the shoulder c4 until the proper instant is reached for the movement of the mercury in the second tube. At this instant the upward movement of the pin b releases the shoulder c4 and allows the cam to move to the position shown in Fig. 6.

It will be seen that by properly arranging the contacts in the tube the length of time durinen which the circuit is closed may be adjustedJ as desired. Furthermore, if the driv-y ing memberhas an intermittent motion, as when driven by the escapement mechanism of a clock, instead of a continuous motion,

, the contact may be so arranged that the intervals of rest occur when-the clrcult 1s closed or opened, as desired.

Many changes may be made in the con'- stru'ction and relative arrangement ofthe parts ofthe device, and consequently l do not desire to limit myself to the particular construction a`nd arrangement of parts here shown, but aim in the appended claims to cover all modiiications which are Within the scope of my invention.

What l claim as new, and desire to secure by Letters Patent oi the United States, is-- l. In a contact device, an endless closed tube having opposite portions bent so that its sides `cross at an angie to each other, contacts mounted within said tube, mercury contained within said tube, and means for rocking said tube.

2., In a contact device, an endless closed tube, contacts mounted within said tube, mercury contained within said tube, and mechanism for rocking said tube with a reciprocating motion, said tube being shaped to cause the mercury to circulate through the tube always in the same direction when the tube is rocked.

3. In a contact device, two endless closed tubes, mercury contained in each tube, contacts arranged in onel tube to be engaged by the mercury when the tube has been rocked, contacts arranged in the other tube to be en gagedmomentarily by the mercury while the tube is being rocked, and means for simultaneously rocking both tubes.

4. In a contact device, two endless closed tubes each having opposite portions bent so that the sides of each tube cross at an angle to each other, the sides of one tube crossing at greater angle than those of the other, contacts mounted in each tube, mercury contained within each tube, and means for simultaneously rocking said tubes.

5. In a contact device, a closed tube, contacts mounted therein, mercury contained within said tube, driving means, connections between said means and said tube whereby said tube is gradually rocked by said driving means and then released, and means forl roducing a quick movement of said tube w en released.

6. In a contact device, a closed tube, contacts mounted therein, mercury contained within said tube, means for rocking said tube, and connections between said rocking means and said tube whereby a gradual and then a sudden movement of said tube is produced.

7. In a contact device, a pivotally-mount-. ed closed tube, contacts mounted therein, mercury contained within said tube, means for rocking the center of gravity of said tube to either side of its support, and means for releasing said tube topermit its continued movement by gravity.

8; ln a contact device, an endless closed tube having opposite portions bent so that its sides cross at an angle to each other, contacts mounted within said tube, mercury contained `within said tube, means for rocking said tube, and connections between said rockin means and said tube whereby each side a ternately is gradually brought to a substantially horizontal position and then is moved quickly through said position.

9. ln a contact device, an endless closed tube, contacts mounted therein, mercury contained in said tube, a rotating member, a

pin carried thereby, a member rigidly secured to said tube and adapted to be engaged and rocked by said pin, said member being arranged to be released by said pin on reaching a predetermined position, and means for producing a quick movement of said member when released.

l0. ln a contact device, a pivotally-mounted closed tube arranged with its center of gravity above its point of support, contacts in said tube, mercury contained in said tube, a rotating member, a pin carried thereby, and a notched cam secured to said tube and adapted to be engaged, rocked and released by said pin.

ln witness whereof i have hereunto set my hand this29th day of 0ctober, 1904.

' KNUT TQRNBERG.

"Witnesses: Y

donn A. itineranti-s, Jr., DUGALD Meli. McnrLLoP IIO 

